Recently in another thread jim beam claimed that the following features:
"...over-center cam locking, serrated faces, thread lock..."
were developed in quick-releases due to the emergence of modern disc brakes
on push-bikes.
Now some of these assertions are false on their face - for thread locking
one has only to look at the clever wing/spring nut on campagnolo record
hubs; and serrated locknuts and qr ends were in use long before anything
except freewheels clicked. The over-centre cam locking is not patently
visible. It did, however, seem wrong to me - all the qr's on the bikes I
have owned felt this way when I closed them; and so it did not surprise me
when...
....he was quickly corrected by a number of posters, but, being jim beam,
claimed
a) they were all wrong, and he was right; and
b) he had sold the single hub on which he based his claim and so could not
prove he was right, but he would if he still had it.
The hub (actually the qr) in question was described as "...the old straight
lever campy...".
Posters replied that they had used this hub and it DID have an over-centre
cam action.
jim beam did the deny, deny, deny thing.
Well, I just took apart a few qr's, which pre-date modern disc brakes, and
measured them. One Campagnolo Record, one Campagnolo Tipo, one MM Atom, and
one Zeus; all except the Zeus have straight levers.
First thing I did was close the qrs on a fork, with a hub in between. The
qr levers, when closed, were about 10 degrees past the perpendicular to the
hub axle (closer to the fork).
Then I disassembled the qrs, removed the spindles, replaced the lever and
retaining nut or C-clip, and mounted them in a vice. I took a
dial-test-indicator and placed the ball on the centre-line of the cam, and
watched the DTI needle as I rotated the lever.
All of the qr's showed that when the lever was in the same position as a
fully-closed qr on a hub, they had passed the maximum cam excursion from the
pivot centre. One in particular - the MM Atom - was past the maximum when
the lever was at 90 degrees.
This last qr came from a Normandy large flange hub, which has serrated faces
on both the locknuts and the qr ends.
Now, if anyone wishes, I will post (urls to) digital photos, but it is quite
possible jim beam will complain about this, as they are in .jpg format, and
I may have to use an indirect link, both of which he has had difficulty
handling. I predict he will instead suggest a better way to settle this
matter of fact will be to "...fight. come on, be a man. come out to the
parking lot..."